Replace C6 transmission shift shaft seal??


I am no expert on transmissions, so need some advice.

My C6 is leaking fluid from the shifter shaft and from the band adjustment screw right next to the shift shaft. I have dropped the transmission oil pan and now have access to the internals. What is the next step? Do I have to drop the valve body? If I do, any tips to ensure I do it the right way?

To remove the shaft, am I just releasing that retaining nut (with the blue arrow in the image) or is there more to it?

What about the leak around the band adjustment screw. I have seen some photos of band screw retainer nuts that look like they have a built in seal/gasket. Is that the problem here?

Any advice appreciated.


The valve body does not need to be removed…but, it might make it a bit more accessible. Take the 1/2 nut off the outside for the Kickdown. The Remove the 7/8 nut at the blue arrow. All the linkage will come out. You have the lipseal in the case and also the kickdown shaft has an o-ring that fits in the end of the shift shaft. When putting hte shafts back in you will have to fanagle the kickdown cam to in between the post and the plunger.

Use a 5/16 wrench to hold the band adjustment stud steady while you loosen the nut a few turns. Turn the stud in until snug. Then loosen about 1 3/4 turns. I like to make a mark on the stud with a paint pen so I can easily count the turns. After adjustment is made, spray some brake-clean behind the nut to clean it. Then squirt a dab of RTV between the nut and case. While holding the stud with the 5/16 wrench tighten to nut to lock it in place.

Great info, thanks!

I did remove the valve body. Otherwise I just could not get any leverage on the 7/8 nut. Once the VB was out it was easy. Now, how do you get that seal out of the case. It is in there really tight. I don’t want to scar the case.

I sealed the band adjustment screw with RTV as you suggested.


Long heavy screw driver. Just be careful not to gouge the case with the tip of the screw driver.

Did you readjust the band to 1 3/4 turns out?

I didn’t adjust the band. When I released the locknut, the adjustment screw didn’t move so I left it where I was. Should I still readjust?